Automatic instantaneous water heating and storage system.



E. S. STACK.-

AUTOMATIC INSTANTANEOUS WATER HEATING AND STORAGE SYS TEIVI.

APPLICATION TILED JAN-20, I914.

1,237,403. Patented Aug. 21, 1917.

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APPLICATION FILED v1.20, 1914.

1,237,403. I Patented Aug. 21, 191?.

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AUTOMATIC INSTANTANEOUS WATER HEATING AND STORAGE SYSTEM.

Specification of Letters Patent Patentgd Aug. 21, 1917.

Application filed January 20, 1914. Serial No. 813,185.

To all whom it may concern:

Be it known that I, ELMER S. STACK, a

citizen of the United States, and a resident of Somerville, in thecounty of Middlesex and State of Mascsachusetts, have inventedcertainnew and useful Improvements in Automatic Instantaneous WaterHeating and Storage Systems, of which the following is a specification.

, The object of the present application is to provide a waterheatingapparatus which is capable of supplying heated water in either large orsmall quantities according to the demands made upon the apparatus.As-illustrating the purposes and uses of this invention I may state thatit is partieularlydesigned for such institutions as gymnasiums, hotels,clubs and the like where the demands for hot water for bathing and otherpurposes vary' between exceedingly wide limits,

and where it is essential that hot water in sufiicient quantities tomeet all demands should be available upon the instant ofthe demand. Fromthis statement of one of the purposes of my invention, it will beunderstood that my general object is to provide an apparatus from whichwater sufiiciently hot to meet the requirements of the service canbeobtained at any instant and in any quantities required, undercircumstances where the demands as to quantity vary within exceedinglywide limits. It is also a part of my object to provide such a heatingapparatus for a circulating hot water system, bywhich the Water in thewhole. system may be kept.

hot, and one by which the fuel or other agent used for heating the wateris not wasted temperature of the water will not be raised to so high adegree as to endanger the integrity of the apparatus by generation ofsteam nor to a higher de rec than that required for the purposes orwhich the hot water is intended' a The invention briefly stated consistsin the combination of a hot water container, with a plurality of waterheaters, and automatic means for putting one or more'ofsuch heaters intoor out of operation according to the demands made upon theapparatus. Inthe accompanying drawings I have shown the preferred embodiment of myinvention with out thereby intending to limit the working out of theinvention to that particular embodiment.

Figure 1 is an elevation showing in a somewhat diagrammatic manner theentire apparatus. I

Fig. 2 is an elevation partly in section showing in detail a form ofwater heater which I propose to use in connection with and as one of theelements of my apparatus. Fig. 3 is a vertical sectional view of thewater container illustrating a form of automatic means for putting theseveral heaters successively into and out of operation.

The same reference characters indicate the same parts in all thedrawings.

In the drawings,l represents a container adapted to contain a body ofwater, such container being of the general character commonly employedfor domestic use. It is equipped with an inlet pipe 2 for supplyingwater to be heated, which pipe extends into the container Well towardthe bottom thereof, and with hot water circulating pipes 3 and :1, oneof which is the outlet pipe for conducting the heated water to theplaces where such water is to be used, and the other of which is thereturn pipe.

5, 6, 7 and 8 represent water heaters which for convenience ofillustration are shown in Fig. 1 as being located all in the same plane,but-Which in practice maybe located in that arrangement orin any othermanner permitted or required by the restrictions of the space in whichthe apparatus is installed.

Such heaters are 'fed with the colder water from the bottom of the tank,supplied by a pipe 9 from which branches 10,- 11, 12 and 13 lead to theseveral heaters. The hot waterdelivered from the heaters flows fromoutlet pipes 14, 15, 16 and 17 respectively, all of g which pipes areshown as joined with a single connecting pipe or conduit leading backtothe tank at or near the upper end thereof where the hot water collects.My

present invention is not limited to the means by which the hot water isdelivered from the heaters tothe tank or tothe hot water supply pipes.Thewater from the heaters may be delivered in other ways than thatherein illustrated, such as by separate connections from each heaterleading independently to the tank, or to-the hot water delivering pipesoutside of the tank, orthe conduit 18 or its equivalent may be connectedto one or more of the pipes which conduct the heated water from thetank. If the hot water delivery conduits from the heaters are connectedto the outlet pipes from the tank outside of the tank, I would prefer touse for the purpose of so connecting them a connection having thecharacteristics of the connection shown and described in my UnitedStates patent for water connections,-No. 1,109,946, granted September8,1914.

Any satisfactory water heater may be used for the purposes of thisinvention, and I do not therefore restrict this invention to acombination of any particular heater with the other elements of thecombinationf I may say, however, that the type of heater which I preferto use is that of which the principles are set forth in my patent of theUnited States No. 1,125,758, granted J anuary 19, 1915, for waterheater. Such heater, which is shown somewhat in detail in Fig. 2,includes a bottom header 19, a top header, not shown but similar andoppositely arranged to the bottom header, and a cluster of tubes 20extending from one header to the other in nearly direct lines so as topermit a free and rapid flow of water, but somewhat inclined so as tocross and intercept the currents of heated gases rising from a gasburner 21 suitably arranged in the base of the heater.

Assuming for convenience that the heater illustrated in Fig. 2 is theheater 5, it will be seen that the supply pipe 10 through which coolwater from the bottom of the tank 1 is conducted, leads to the lowerheader 19, and that the hot water outlet pipe 14 leads from the upperheader. All the other heaters shown may be .and preferably areduplicates of the heater 5 here particularly described.

Each heater-has its own independent gas burner 21, and these burners ofthe several heaters are fed respectively by supply pipes 22, 23, 24 and25 which lead or may lead from a common gas main 26 and are so placed asto cooperate with thermostatic valve controlling means governed by theheat of the water in the tank and locatedat respectively'differentlevels in the tank.

I do not limit my invention to the use in the combination hereinafterclaimed of any particular or specific thermostatic valve controllingmeans, but for the purpose of illustrating an'operative means of thischaracter, I have shown a particular thermostatic mechanism which I willnow describe, choosing for this detailed description the particularthermostatic device which controls the flow ofgas through the pipe 22 tothe heater 5. This controlling device includes a valve casing or housing27 which is mounted externally upon or near the tank 1 and is providedwith two internal chambers, 28 and 29, respectively. 'To one of thesechambers is connected that portion of the pipe or conduit 22 which leadsfrom the main and is here particularly designated as 22, and from theother of these chambers leads the part 22 of the conduit which runs tothe heater. Between the chambers is a partition having an aperturesurrounded by a valve seat with which cooperates a valve 30. A spring 31acts on this valve and tends normally to close it. The thermostaticelement consists of a tube 32 extending through the wall of the tankinto the interior thereof, and containing a rod 33 fastened to the innerend of the tube. Such rod acts through multiplying levers 34 and 35pivoted upon brackets which form part of the valve casing structure, theformer lever being directly acted upon by the rod and in turn actin onthe second lever, and the latter lever eing engaged with the stem 36 ofthe gas valve and arranged to bear against an adjustable abutment 37thereon. WVhen the thermostatic tube contracts upon cooling, it exerts athrust on the rod 33 which bears on the short arm of the lever 34. Thelong arm of the lever acts on the short arm of the lever 35, and thelong arm of the latter moves the valve 30 against the pressure of thespring 31 in the direction which causes the valve to be opened.Thereupon gas is admitted to the burner of the heater which iscontrolled thereby. Expansion of the tube 32 due to heating relieves therod 38 and allows the spring 31 to close the valve. The thermostaticcontrolling means for the burners of the other heaters are shown here asbeing the same as the controlling means above described, and theirseveral parts are designated by the same reference characters as'thecorrespond ing parts of the device above described.

In order that the gas may be ignited at the burners upon being admittedthereto after having been shut oil, I provide a p lot burner in eachheater near the-main l urner therein, such pilot burner being suppl edby pipes 38, 39, 40 and 41, which branch from a supply pipe 42leading'from the gas. mam 26 at a point where the flow is not affectedby the operation of the thermostat] controlling means.

- It will be observed from the drawings that the thermostat controllingthe gas supply for the heater 5 is at a high level in the tank 1, thatthe thermostat for the heater 6 is at a lower level, that for. theheater 7 at a still lower level, that for the heater 8 at the lowestlevel of all. This illustrates a condition which is a fundamental one nthis invention, that several heaters are provided for heating the waterin the tank, and that these heaters are severally controlled by thetemperature of the water in different parts of the tank. It is not anessential feature be understood. When the entire body of Water in thetank is cold, all of the fuel controlling valves are openedby thecontraction of their several controlling thermostatic elements and allof the heaters are thereby put into operation, all acting simultaneouslyto take cold water from thebottom of the tank and return the waterheated to the top of the tank. When the water at the level of theuppermost thermostat becomes sufficiently heated,'the valvecontrolled bythat thermostat is shut offand the heater 5 is put out ofoperation. Thenif the hot water is not drawn off from the tank as fast as it is heatedby the remaining heaters, the

hot water occupies more and more of the.-

volume of the tank extending from the top downward until one afteranother of the thermostats are caused in succession first to reduce andthen to shut off the supply of fuel -to,theheaters which they control,until finally only 'suflicient of the heaters are left in operation tosupply hot water in sufficient quantities to meet the demand. When thereis no demand, all of the heaters are shut off when the entire volume ofwater in the tank has become heated to the desired point. When the hotwater is drawn off from the top of the tank, cold water to supply thedrain is admitted to the lower part of the thermostatic element andputting the heater 8 into operation. If the capacity of' this heater isnot sufficient to supply the demand for hot water, the next thermostatis actuated and the next heater in the series is made operative, and soon until all the heaters are put into operation if the demand is greatenough to require-the cooperation of i Similarly, if the body of so manyheaters. water in the tank becomes cool by radiation, the cooler watersettles in the bottom of the tank and when its temperature issufliciently low the heater 8 is put in operation for a period longenough to raise the tank tem'- perature to the desired point, when it isagain automatically discontinued.

It will thus be seen that I have provided means by which 'a large bodyof water may be quickly heated to the required temperature automaticallyand with a. relatiyely small expenditure of fuel. It will also beappreciated that my heating system provides a means by which enough heatmay be automatically provided to raise the temperature of as great avolume of water as can pass through the tank to the desired degree, asrapidly as it can be drawn from the tank, while at the same timeenabling the amount of fuel consumed to be reduced when the demand islight to heat only the quantity of water required. In this way thegreatest possible fuel economy is secured and danger of overheating thewater and of generatlng steam which might burst the tank or loosen thejoints of the piping is avoided. It is my intention to provide in eachsystem or apparatus consisting of the combination of elements abovedescribed, a number of heaters so great that their combined capacity isas great as the total discharge capac- -ity of the tank. The system'orapparatus may be made as large as desired within practical manufacturinglimits to supply any amount of water in a given time, or a number ofsuch systems may be installed where it is not practicable to have asingle system of sufficiently-great capacity.

I wish it to be understood that in describ-- ing the heating apparatusfor the heaters as a gas burner, and the heating agent as gas, that Ihave not intended to limit my invention to this or any other particularheating means or agent. The terms gas burner,

fgas, and gas controlling valve used in the foregoing description aremerely terms of illustration having no limiting significanoe.

In the broader aspect of the invention, the gas burner may beconsideredas typical of some or any heating means or device, the combustible gasor fuel for supplying the burner as being typical of any heating agentwhich might be used for supplying or gencrating heat, and thethermostatic controlheater, causing contractionof the lowermost trol thesupply of heatingagent to the heaters and being themselves controlled bythe temperature of the water in the tank. I do not wish to restrictthe'invention to the use of heaters which require a fiame to generate orsupply the heat, for I include within the scope of the invention allother heating defuel developed in the heater, orv a previously heatedfluid. 7

Likewise I desire it to be clearly understood that my invention may becarried into 'vices in which the heat-giving agent may be either gaseousproducts of combustion of effect with the use of many other sorts ofthermostats and thermostatically controlled.

valves than those herein illustrated and par ticularly described. Thepipe connections may otherwise be arranged in different manners, all ofwhich are within the scope of my invention, provided the essentialprinciple is maintained of. having a series of heaters which arecontrolled in operation 7 according to the temperature of the fluid tobe heated in different parts of the tank or container.

It is of course to be understood also that the invention can be applied-.to-

heating other fluids than water, since it is intended to be used forsupplying heat to any fluid to which for any purpose it may be desirableto supply heat.

I can best illustrate and explain the commercial and practicaladvantages of the present invention by mentioning the systems which havehitherto been exclusively in use, so far as I am aware, for the purposeof providing hot water in sufiicient quantities to meet sudden and greatdemands. One previously used mode of meeting the condition described hasbeen to provide a large tank or container capable of holding say fivehundred gallons, and a heater in connection therewith of sufficientcapacity to keep this large volume of Water hot. Such a system is inefiect a heat storage system, wherein a large body of water is heated tothe required temperature in anticipation of the expected demand andbefore the demand has been made upon it. To do this requires the initialexpenditure of a large amount of heat and the continual expenditure of aconsiderable amount of heat before any water at all is drawn from thetank. The system must always be in condition to meet the maximum demand,even at those times when the demand is light or there is no demand atall.

One of the advantages of my apparatus orsystem is the saving of fuelover such a system as that described.v My heating apparatus is equallyapplicable to a circulating hot water system, wherein the pipes withwhich the hot water taps or faucets are connected form a circuit withthe water container and permit a continuous gravity thermal flow,whereby hot water is always accessible to all the taps, even those mostdistant from the heater. My a paratus which includes the combination 0 aplurality of heating elements with a water container, permits arelatively-very small container to be used in a circulating system uponwhichthe demands may be very sudden and great. With my system I canemploy a water container hav-- mg only asmall fraction'of the volume ofthe tank required under the old system; One

of the heaters is ordinarily sufiicient to keep the small body of waterin this relatively small container, and also the body of watercirculatingthrough the hot water pipe'system, at the requiredtemperature. No great amount of fuel'is required when first putting thesystem in operation to heat this relait is aintained at this temperaturewhen the emand is light, by one heater operating either intermittentlyor at less than its full capacity, under the control of its thermostat.In this way the water is kept in condition for instant use when drawn insmall quantities. When the demand 'is suddenlyincreased the other heatofwater-to the desired ers are immediately called into operation and theybecome effective to heat a larger quantity of water before thepreviously heated supply is exhausted. Thus the persons desiring to usehot water are not re quired to wait after turning on the tap until thewater runs hot, there is no possibility of exhausting the supply of hotwater, and the fuel consumption is kept down to the least possibleamount.

The other commonly used means for the purpose specified is aninstantaneous Water heater which is put in operation only when water isdrawn, and has a large enough fuel burner to heat the water to thedesired temperature when the maximum flow passes through the heater.Such a heater cannot be connected with a circulating system, andtherefore the water in the pipe between the heater and the tap isallowed to cool off when no water is being drawn. Thereupon when onedesires even a small quantity of hot water he must draw off the coldwater already in the pipe before the hot water flows, and the burner ofthe heater is operating at full capacity during all this time, wastingfuel and heating enough water riot only to supply the demand of the userbut also to take the place of the cold water previously lying dead inthe pipe system. The heat in the water which lies betweenthe heater andthe tap becomes dissipated and lost to a greater or less extent in theinterval between closing of the tap and opening it again when more wateris wanted. A stem of this sort having a large ca acity frequently emloys" large pipes, whic contain a relatively arge volume of water.

water appears at the tap, are large items of 7 Waste, particularly ifonly small quantities of water are needed each. time the system isoperated. With my heater there is no waste of water because thecirculating system maintains hot water at all of the taps of the system.There is no extra expenditure of gas when small quantities of water aredrawn, since the hotwater already in the system is. suflicient in volumeto supply small demands. In the case of large demands the heating agentis turned on only gradually and in amounts exactly regulated to thevarious demands. The pilot lights employed in connection with my heatersare not a-source of waste because they furnish a certain amount of heatwhich is absorbed by the water which is in condition to circulateconstantly through the heaters and the hot water system. Anotheradvantage of my system is that if any part of any heater should fail andrequire repairs the entire 4 quantity of liquid, a plurality of heatingdevices connected in parallel with said container, and means controlledby the temperature of the liquid in diflerent levels in the containerfor putting said heating devices successively into and out of operation.

2. A liquid. heating and storage system comprising in combination acontainer adapted to liquid, a series of liquid heating devices arrangedto receive liquid from said container and deliver it to the place ofdemand, and automatic controlling means for causing more or fewer ofsaid heating devices to be put into operation according to the demandfor the heated liquid.

3. A water heating apparatus comprising a water container, a. watercirculating pipe system with which said container is connected, aplurality of water heaters each having its own heat delivering element,said heaters being all connected to receive water from the container andheat the same, and thermally controlled means for admitting the heatingagent to the said heat delivering elements to an extent corresponding todifferences in temperature between the water at different levels in thecontainer.

4:. A heating apparatus comprising in combination, a l1qu1d container,heating 'means in circulating connection with said container adapted toheat the liquid in the container, a plurality of heat dominating valvesfor determining the quantity of heat delivered to'the liquid in saidheating means,

and thermally controlledmeans for operating said heat dominating valves,severally controlled by the temperature of the liquid at respectivelydiflerent levels in the container. I

5. A heating apparatus for liquids comprising a liquid container, aplurality of heat delivering means for imparting heat to the liquid insaid container, a heat dominating valve for each of the said heatdelivering means, and means controlled by the temperature of the liquidin the container for opening and closing more or fewer'of said valvesaccording to the temperature of the liquid in different parts of thecontainer.

6. A hot water system'comprising in com bination, a water container, acirculating pipe system connected with said container, a plurality ofgas water heaters each arranged to take water from the bottom of saidcontainer and; deliver heating water to the upper part thereof, each ofsaid heaters having smaller capacity than the discharge capacity hold instorage a quantity of of the pipe system, and the combined capacity ofall the heaters being as great as that of the pipe system, a heatcontrolling valve for each heater and a thermostat independentlyconnected to control each of said valves,'the thermostats being respecinthe container at diflerent levels, whereby to put more or fewer of theheaters in operation according as the average of the temperatures ofsuch levels is respectively low or high.

' 7. A water heating apparatus comprising a water container, a heaterarranged to take water from the lower part of said container and returnthe water to an elevated part-of the container or to an outlet pipeleading therefrom, whereby water is provided at the top of thecontainerat a high temperature, an auxiliary water heater also arrangedto receive water from the lower part of the tank and deliver it to theupper part of the tank, a valve for controlling the heat furnished insaid auxiliary heater, and thermostatic means in thermal contact withthe water at an elevated point in said container,

arranged and connected to operate said valve.

8. A liquid heating apparatus compris ng a liquid container, a heater incirculating --conneotion with said container, an'auxiliary heater alsoin circulating connection with. the container, and thermostatic meanscontrolledby the temperature of liquid in the container for governingthe operation of said auxiliary heater according as the first namedheater is sufiicient or not to furnish the required amount of heat tothe liquid.

9.;A liquid heating apparatus comprising a liquid container havin adelivery outlet, a heater arranged to receive liquid from said containerand return the liquid thereto in a heated condition at a point near thesaid decan be supplied by the first heater.

10. The combination of ajpipe system, a plurality of water heatersarranged in parallel adapted to deliver water simultaneously to saidpipe system, and means controlled by the temperature of the water forputting said heaters severally into and out of operation.

11. In a fluid heating system, the combination of a plurality of heatingelements all arranged in parallel in the same system, means forgoverning the supply of heat furnished by each of said elements, thesaid governing means for each element being independent of thecorresponding means for any other element, and means controlledautomatically for operating said governing" 'tively affected by thetemperature of water I livery outlet, an auxiliary heater likewise meansto regulate the supply of heat furnished in proportion to the quantityof heat-- ed liquid demanded.

12. A liquid heating and storage apparatus, comprising means forcontaining and supplying a body of heated liquid havin an inlet foradmitting liquid to be heate a plurality of heatin elements, anindependent heat controller %or each ofsaid elements, and a plurality ofthermostatically operated devices located at difierent heights in saidcontaining means, and each connected to operate one of said controllers.

13. An apparatus for providing heated liquid, comprlsing a container forthe liquid, heating means connected and arranged for heating the liquidin said container, and a plurality of distinct heat controlling meansarranged for operation severally and co1lectively to increase anddiminish the amount of heat furnished by said heating means and meanscontrolled by the temperature of the liquid at a plurality of heights insaid container for operating independently the several heat-controllingmeans.

14. A liquid heating apparatus comprising a container for the liquid,means for heating the container, a plurality of thermostats located atdifferent heights in said container, and means operated by saidthermostats for cumulatively increasing and diminishing the amount ofheat delivered by said heating means according to the temperatures inthe liquid acting onthe several thermostats.

In testimony whereof I have aifixed my signature, in presence of twoWitnesses.

.ELMER s. STACK.

